/*=========================================================================
 *
 *  Copyright UMC Utrecht and contributors
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *        http://www.apache.org/licenses/LICENSE-2.0.txt
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 *=========================================================================*/
#ifndef itkNormalizedGradientCorrelationImageToImageMetric_h
#define itkNormalizedGradientCorrelationImageToImageMetric_h

#include "itkAdvancedImageToImageMetric.h"
#include "itkSobelOperator.h"
#include "itkNeighborhoodOperatorImageFilter.h"
#include "itkPoint.h"
#include "itkCastImageFilter.h"
#include "itkResampleImageFilter.h"
#include "itkOptimizer.h"
#include "itkAdvancedCombinationTransform.h"
#include "itkAdvancedRayCastInterpolateImageFunction.h"

namespace itk
{

/**
 * \class NormalizedGradientCorrelationImageToImageMetric
 * \brief An metric based on the itk::NormalizedGradientCorrelationImageToImageMetric.
 *
 *
 * \ingroup Metrics
 *
 */

template <class TFixedImage, class TMovingImage>
class ITK_TEMPLATE_EXPORT NormalizedGradientCorrelationImageToImageMetric
  : public AdvancedImageToImageMetric<TFixedImage, TMovingImage>
{
public:
  /** Standard class typedefs. */
  typedef NormalizedGradientCorrelationImageToImageMetric       Self;
  typedef AdvancedImageToImageMetric<TFixedImage, TMovingImage> Superclass;
  typedef SmartPointer<Self>                                    Pointer;
  typedef SmartPointer<const Self>                              ConstPointer;

  /** Method for creation through the object factory. */
  itkNewMacro(Self);

  /** Run-time type information (and related methods). */
  itkTypeMacro(NormalizedGradientCorrelationImageToImageMetric, AdvancedImageToImageMetric);

/** Types transferred from the base class */
/** Work around a Visual Studio .NET bug */
#if defined(_MSC_VER) && (_MSC_VER == 1300)
  typedef double RealType;
#else
  typedef typename Superclass::RealType RealType;
#endif

  typedef typename Superclass::TransformType           TransformType;
  typedef typename TransformType::ScalarType           ScalarType;
  typedef typename Superclass::TransformPointer        TransformPointer;
  typedef typename TransformType::ConstPointer         TransformConstPointer;
  typedef typename Superclass::TransformParametersType TransformParametersType;
  typedef typename Superclass::TransformJacobianType   TransformJacobianType;
  typedef typename Superclass::InterpolatorType        InterpolatorType;
  typedef typename InterpolatorType::Pointer           InterpolatorPointer;
  typedef typename Superclass::MeasureType             MeasureType;
  typedef typename Superclass::DerivativeType          DerivativeType;
  typedef typename Superclass::FixedImageType          FixedImageType;
  typedef typename Superclass::FixedImageRegionType    FixedImageRegionType;
  typedef typename Superclass::MovingImageType         MovingImageType;
  typedef typename Superclass::MovingImageRegionType   MovingImageRegionType;
  typedef typename Superclass::FixedImageConstPointer  FixedImageConstPointer;
  typedef typename Superclass::MovingImageConstPointer MovingImageConstPointer;
  typedef typename Superclass::MovingImagePointer      MovingImagePointer;
  typedef typename TFixedImage::PixelType              FixedImagePixelType;
  typedef typename TMovingImage::PixelType             MovedImagePixelType;
  typedef typename itk::Optimizer                      OptimizerType;
  typedef typename OptimizerType::ScalesType           ScalesType;

  itkStaticConstMacro(FixedImageDimension, unsigned int, TFixedImage::ImageDimension);

  /** Types for transforming the moving image */
  typedef typename itk::AdvancedCombinationTransform<ScalarType, FixedImageDimension>  CombinationTransformType;
  typedef typename CombinationTransformType::Pointer                                   CombinationTransformPointer;
  typedef itk::Image<FixedImagePixelType, itkGetStaticConstMacro(FixedImageDimension)> TransformedMovingImageType;
  typedef itk::Image<unsigned char, itkGetStaticConstMacro(FixedImageDimension)>       MaskImageType;
  typedef typename MaskImageType::Pointer                                              MaskImageTypePointer;
  typedef itk::ResampleImageFilter<MovingImageType, TransformedMovingImageType>        TransformMovingImageFilterType;
  typedef typename TransformMovingImageFilterType::Pointer TransformMovingImageFilterPointer;
  typedef typename itk::AdvancedRayCastInterpolateImageFunction<MovingImageType, ScalarType> RayCastInterpolatorType;
  typedef typename RayCastInterpolatorType::Pointer                                          RayCastInterpolatorPointer;

  /** Sobel filters to compute the gradients of the Fixed Image */
  typedef itk::Image<RealType, itkGetStaticConstMacro(FixedImageDimension)> FixedGradientImageType;
  typedef itk::CastImageFilter<FixedImageType, FixedGradientImageType>      CastFixedImageFilterType;
  typedef typename CastFixedImageFilterType::Pointer                        CastFixedImageFilterPointer;
  typedef typename FixedGradientImageType::PixelType                        FixedGradientPixelType;

  /** Sobel filters to compute the gradients of the Moved Image */
  itkStaticConstMacro(MovedImageDimension, unsigned int, MovingImageType::ImageDimension);
  typedef itk::Image<RealType, itkGetStaticConstMacro(MovedImageDimension)>        MovedGradientImageType;
  typedef itk::CastImageFilter<TransformedMovingImageType, MovedGradientImageType> CastMovedImageFilterType;
  typedef typename CastMovedImageFilterType::Pointer                               CastMovedImageFilterPointer;
  typedef typename MovedGradientImageType::PixelType                               MovedGradientPixelType;

  /** Get the derivatives of the match measure. */
  void
  GetDerivative(const TransformParametersType & parameters, DerivativeType & derivative) const override;

  /**  Get the value for single valued optimizers. */
  MeasureType
  GetValue(const TransformParametersType & parameters) const override;

  /**  Get value and derivatives for multiple valued optimizers. */
  void
  GetValueAndDerivative(const TransformParametersType & parameters,
                        MeasureType &                   Value,
                        DerivativeType &                derivative) const override;

  /** Initialize the Metric by making sure that all the components
   *  are present and plugged together correctly.
   */
  void
  Initialize(void) override;

  /** Write gradient images to a files for debugging purposes. */
  void
  WriteGradientImagesToFiles(void) const;

  /** Set/Get Scales  */
  itkSetMacro(Scales, ScalesType);
  itkGetConstReferenceMacro(Scales, ScalesType);

  /** Set/Get the value of Delta used for computing derivatives by finite
   * differences in the GetDerivative() method.
   */
  itkSetMacro(DerivativeDelta, double);
  itkGetConstReferenceMacro(DerivativeDelta, double);

  /** Set the parameters defining the Transform. */
  void
  SetTransformParameters(const TransformParametersType & parameters) const;

protected:
  NormalizedGradientCorrelationImageToImageMetric();
  ~NormalizedGradientCorrelationImageToImageMetric() override = default;
  void
  PrintSelf(std::ostream & os, Indent indent) const override;

  /** Compute the mean of the fixed and moved image gradients. */
  void
  ComputeMeanMovedGradient(void) const;

  void
  ComputeMeanFixedGradient(void) const;

  /** Compute the similarity measure  */
  MeasureType
  ComputeMeasure(const TransformParametersType & parameters) const;

  typedef NeighborhoodOperatorImageFilter<FixedGradientImageType, FixedGradientImageType> FixedSobelFilter;
  typedef NeighborhoodOperatorImageFilter<MovedGradientImageType, MovedGradientImageType> MovedSobelFilter;

private:
  NormalizedGradientCorrelationImageToImageMetric(const Self &) = delete;
  void
  operator=(const Self &) = delete;

  ScalesType                  m_Scales;
  double                      m_DerivativeDelta;
  CombinationTransformPointer m_CombinationTransform;

  /** The mean of the moving image gradients. */
  mutable MovedGradientPixelType m_MeanMovedGradient[MovedImageDimension];

  /** The mean of the fixed image gradients. */
  mutable FixedGradientPixelType m_MeanFixedGradient[FixedImageDimension];

  /** The filter for transforming the moving images. */
  TransformMovingImageFilterPointer m_TransformMovingImageFilter;

  /** The Sobel gradients of the fixed image */
  CastFixedImageFilterPointer m_CastFixedImageFilter;

  SobelOperator<FixedGradientPixelType, itkGetStaticConstMacro(FixedImageDimension)>
    m_FixedSobelOperators[FixedImageDimension];

  typename FixedSobelFilter::Pointer m_FixedSobelFilters[itkGetStaticConstMacro(FixedImageDimension)];

  ZeroFluxNeumannBoundaryCondition<MovedGradientImageType> m_MovedBoundCond;
  ZeroFluxNeumannBoundaryCondition<FixedGradientImageType> m_FixedBoundCond;

  /** The Sobel gradients of the moving image */
  CastMovedImageFilterPointer m_CastMovedImageFilter;
  SobelOperator<MovedGradientPixelType, itkGetStaticConstMacro(MovedImageDimension)>
    m_MovedSobelOperators[MovedImageDimension];

  typename MovedSobelFilter::Pointer m_MovedSobelFilters[itkGetStaticConstMacro(MovedImageDimension)];
};

} // end namespace itk

#ifndef ITK_MANUAL_INSTANTIATION
#  include "itkNormalizedGradientCorrelationImageToImageMetric.hxx"
#endif

#endif
